Window structures



M. J. NARDULLl WINDOW STRUCTURES Filed sept. 1e, 1957 iii E L Q United States Patent WINDOW STRUCTURES Michael J. Nardulli, Elmwood Park, Ill., assignor to said Michael J. Nardulli, Angelo F. Naples, and Peter F. Nardulli, as trustees Application September 16, 1957, Serial No. 684,133

1 claim. (cl. zo-sz) This invention relates to double hung window structures and particularly to the counterbalancing of the sash thereof by coil spring means.

DoubleA hung window installations of many different types have been counterbalanced through the use of elongated coil springs extended downwardly in appropriate spaces between the edges of the sash and the jambs of the window frame and connected at their lower ends to lower portions of the respective sash. As above pointed out this has been done in many different kinds of double hung windows. As an example, it may be pointed out that in the Silent-Tite double hung window marketed by Curtis Industries under Madsen Patent No. 1,869,760, elongated springs have been mounted in more or less exposed positions to attain the desired counterbalancing action, while in other instances the coil springs have been partially exposed or in some instances, more substantially concealed relationships. An example of a partially concealed spring mounting in double hung Windows is found in the structures disclosed in my co-pending application No. 587,120, led May 24, 1956, now Patent No. 2,828,514, patented August 2, 1957, while a substantially concealed arrangement for the springs has been widely employed in the Master No-Draft metal sash guides that have been widely sold throughout the industry, this arrangement having been manufactured under the Gossen Patent No. 2,158,963. In all such prior structures resilient means acting laterally against the sash function to hold the sash `in adjusted position.

The use of such coiled counterbalancing springs has thus been employed in permanently mounted double hung window installations in the above-mentioned Silent- Tite structure and in the above Master structure, while in the window structure shown in my aforesaid copending application, the sash are both tiltable and removable in character. Other examples might be given as to similar structures. The present invention `is applicable to all of the foregoing general types of double hung -window structures.

In all of the prior double hung window installations of the general type of which I am aware the coil springs for each sash have been anchored at their upper ends near the top of the sash runway and have been connected at the lower ends near the lower end of the sash; and while such arrangements have been widely used and sold in the trade for many years it has been recognized throughout this period that an unsatisfactory counterbalancing action has been attained, particularly with respect to the counterbalancing of the upper sash. Thus, in such prior installations the individual springs have usually been initially made of a length approximately equal to or slightly less than the vertical dimension of the individual sash, and this has been necessary in order to avoid over-extension of the springs in the lowering of the individual sash. In this respect, it may be pointed out that it is generally recognized that coiled springs must not be extended to more than about 1.75 to 2.0 times their original length, depending on the size and ICC "material of the springs, and when extended beyond this point, the springs are stressed beyond the elastic limit of the spring material so that they take a permanent set at a dimension somewhat greater than the original dimension. The strength of the springs is of course selected according to the preference of the maker, and the amount of side tension that is to be elfective on the sash, and one criterion that is often used is to make the springs sufficiently strong so that when they freely support the related sash, the springs will elongate substantially 30% beyond their original length. When prior counterbalancing springs have been originally selected dimensioned as above pointed out, excessive elongation is avoided even when the sash is moved to its lowerrnost position, but when the sash is in its upper position, the spring is under practically no tension so that there is substantially no counterbalance force applied to the sash. Thus when the upper sash is in its upper position with such ia negligible counterbalancing force being applied thereto, the slightest vibration of the building acts to induce a downwardly creeping movement of the sash. The most common situation Where this is found to be objectionable is where the lower sash is partially or fully opened during the summer season and has a protective screen which eifectually closes the lower sash area against entry of insects and the like. Under such conditions it is desirable that the upper sash remain in its uppermost or fully close dposition because otherwise there would be an open area through which insects and the like might enter the room. In view of the foregoing, it is vthe primary object of the present invention to enable coiled spring means to eifectually counterbalance double hung window sash, and related objects are to prevent objectionable downwardly creeping of the upper sash of such an installation and to accomplish this in a simple manner.

Another important object of this invention is to enable a single counterbalancing spring on each side of a window frame to eifectually counterbalance both the upper sash and the lower sash of a double hung window installation, and a more specific object is to enable the spring means acting on the upper sash of a double hung installation to be under tension while the upper sash is in its upper position.

Other and further objects of the present invention will be apparent from the following description and claim, and are illustrated in the accompanying drawings, which, by way of illustration, show preferred embodiments of the present invention and the principles thereof, and what is now considered to be the best mode in which to apply these principles. Other embodiments of the invention embodying the same equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the invention.

In the drawings:

Fig. 1 is a vertical sectional View through a window structure embodying the invention;

Fig. 2 is a fragmentary plan section of the window structure taken along the line 2-2 of Fig. 1;

Fig. 3 is a side elevational view of one of the counterbalance elements;

Figs. 4 and 5 are diagrammatic views illustrating the sash in diiferent positions; and

Fig. 6 is an elevational view of a different form of counterbalance element.

For purposes of disclosure the invention is illustrated in Figs. 1 to 5 of the drawings as embodied in a window structure 20 of the double hung type having a window frame 21 with jambs 22, a head 23 and a sill 24. The basic window structure is of substantially the same kind as that shown in my aforesaid co-pending application in that it has upper and lower sash 25 and 26 that are spprted in yieldably mountedv guide Ychannels y27-and 28, Fig. 2, which are duplicated on the opposite jambs 22, and the sash 25 and A26 are associated with these gide'chaiinel's so that the sash -may'not only be removed, l`b`ut` may also be pivoted inwardly for washing about the `pivots` 25P and 26P in' the manner disclosed in detail my aforesaid co-pending application. The details of structure and operation are morefully disclosed'inmy 4aforesaid `copending application and Vis hereby incorporated by reference in the present application.

` The primary structural distinction is found in the counterbalancing means that are provided under the present invention, and in this respect it may be noted that each of `the yieldable sash guides 27 and 28 has a relatively deep longitudinal groove 30 yformed therein which provides space between the edges of the respective sash and the guideway in and through which elongated 'extensible counterbalancing vmeans may extend. Under ythe present invention such counterbalancing means, as shown in Figs. l to 5 constitute a single elongated coiled lspring 35 having a lateral dimension such that it may t in the deep groove 30 of the guideway. The opposite ends of each spring 35 are attached to the respective sash near the lower edges thereof, and this may be accom- `plished with the sash herein shown by securing the ends of the counterbalancing member 35 to the respective pivots P and 261. The intermediate portions of the -spring 35 extend upwardly in the deep grooves 30 of the guideways, and the bight of the spring 35 extends over anti-friction guide means 40 which as herein shown -is provided by a single pulley mounted adjacent each of kthe ends of the head 23. Such pulleys are so sized and arranged that the straight portions of the spring 35 are guided into the upper ends of the deep grooves 30, and `the upper ends of the guide channels 27 and 28 are, in "the present instance, cut away as at 41 to provide clearance for portions of the pulleys 40.

In Figs. l to 5 the counterbalancing means is in the form of a continuous spring 35, but if desired, the coun- `terbalancing means may be embodied as an extensible member 135 as shown in Fig. 6 wherein end portions are Cit fin the form of coils springs while an intermediate portion I 135A is of a constant length or in other words, is not ystretchable. This portion 135A may be merely a portion of the spring wire that is uncoiled or maybe formed 'as a separate element and attached to the spring sections so as to complete the member 135.

In Figs. 3, 4 and 5 the invention is diagrammatically illustrated in the one proportioning of the parts that has been found to be satisfactory. Thus the spring 35 may be made of a total length that is substantially equal to the height of the window opening, as shown by a comparison -of Figs. 3 and 4, and when attached in the manner above described, it will be apparent that when the sash are in their closed positions, the springs 35 are stressed so as moved to their lower positions, the spring 35 will not be stressed beyond its elastic limit.

In some instances where spring balances are used with double hung windows it has been the custom to provide stop means in the outer sash runway to prevent excessive lowering movement of the sash which might otherwise cause the springs to be excessively tensioned. This same expedient may be used with the present structure as `indicated'bythe'stop screw 47 shown in Fig. 1 of the drawings.

From the foregoingit will be apparent that the. present invention provides for an'improved spring balancing of double hung sash, and `inparticular it will be noted that the inner sash is effective under the present invention to apply upward yielding force to the upper sash even when the' upper sash is in its closed 'position so that the sa'sh will remain in its closed position even though subjected to vibration or other displacing forces.

Thus while I have illustrated and described preferred embodiments of my invention it is to be understood that changes 'and variations may be made by those skilled in `the 'art without departing from the spirit and scope of the appending claim.

I claim:

In a double hung window structure having a frame having a window opening of a predetermined heightwith upper and lower sash slidably guided therein in double hung relation and with vertical clearance spaces along and between the frame and the opposed edges of the 'respective sash, and spring means acting laterally on the sash to'restrain the same against vertical displacement, the improvement whichicomprises an elongated longi tudinally extensible coil spring of a length substantially equal to such predetermened height and disposed at one side of the frame with its opposite ends anchored to `the respective sash, and anti-friction guide means on said frame on said side thereof over which the bight portion of the coil spring extends to apply equalized counterbalancing forces to the respective sash while guiding said coil spring into said clearance spaces.

References Cited in the tile of this patent UNITED STATES PATENTS v943,014 Greear et a1 Dec. 14, 1909 2,232,026 Geber Feb. 1s, v1941 2,605,369 Hansing July 29, 1952 

